<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style lang="less">
        .div1 {
            width: 600px;
            height: 600px;
            background-color: lightpink;
            margin: 0 auto;
        }
    </style>
</head>

<body>
    <div class="div1"></div>
</body>

</html>